The goal of the Diagnostic Core is to provide both comprehensive assessment of subjects with autism spectrum disorders and recruit potential participants in support of the UCLA ACE projects. The Core will draw on the strengths of the programs at UCLA that are addressing the needs of individuals with autism, and the community relationships to identify subjects. Significant institutional support provides key infrastructure and personnel in this endeavor. The Core staff will complete comprehensive assessments on all subjects consistent with ACE requirements using the gold standard diagnostic tools (ADI-R and ADOS), standardized cognitive testing and the Vineland II Adaptive Behavior Scales. The Core staff have demonstrated consistent reliability on the gold standard measures and will insure the quality and integrity of the assessments and administration. The Core staff will also provide training and supervision to externs, psychology interns, and other allied health professional trainees in addition to graduate students and research assistants working on related projects. Also consistent with the common measures, participants will undergo neurogenetic and physical evaluations (utilizing standardized ACE forms provided by NIH), including phlebotomy procedures. This methodology assures efficient, consistent and comprehensive evaluations of all UCLA ACE participants. In addition, recruitment efforts are centralized to identify subjects and controls for ACE projects, coordinate entry into the appropriate studies and facilitate sharing between projects and across sites. Further, because there is overlap between some projects, this facilitates continuity of assessments and maintains relationships with participants. This facilitates retainment with ACE subjects in research and enhances long-term follow-up opportunities for enrollment in projects and programs at UCLA. The Diagnostic Core begins with a summary of objectives, followed by summaries of staffing and the diagnostic tools consistent with best practices and as required by the ACE, resources, recruitment opportunities at UCLA and in the community; justification with the description of services, and administration.